Malicious PDF — malware analysis report

Static analysis result for SHA-256 4666e423c82ef630…

MALICIOUS

PDF

84.4 KB Created: 2021-09-14 11:16:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 165e9703c1a3741706c749c897ac020b SHA-1: 62174e5e82c5910c6d4653646fb3ef4589c6481e SHA-256: 4666e423c82ef63029bb04e56a11b9ee2a7649b1361e4190940e01147b527995
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains embedded JavaScript and a large number of external links, many of which point to compromised websites or disposable hosting, suggesting a phishing or malware distribution campaign. The embedded JavaScript likely facilitates the redirection or download of malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://krisoc.ru/uplcv?utm_term=jak+odzyska%C4%87+usuni%C4%99te+wiadomo%C5%9Bci+sms+android PDF link annotation
    • http://fazendasaojudastadeu.net/fotosempresa/files/33776682078.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/xibozanazisikuzu.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/13331800411.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/78349694161.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/6ag261boch6iub5epr86l5bm34/fupamefozudile.pdfIn PDF document text
    • http://bm-shower.com/userfiles/files/kogikujatosa.pdfIn PDF document text
    • http://tetraeng.it/userfiles/files/bodumixufotube.pdfIn PDF document text
    • http://www.rsvpcatering-ar.com/files/imagesfile/sokixojukebosixagakaji.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed2f930722---kejaje.pdfIn PDF document text
    • https://castilloexterior.net/ckfinder/userfiles/files/gutaso.pdfIn PDF document text
    • https://sofupingame.net/calisma2/files/uploads/gigopax.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/18039804012.pdfIn PDF document text
    • http://chataphan.com/file_media/file_image/file/korotiwadukijo.pdfIn PDF document text
    • http://szhlfz.net/upload/34893518038.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/jexakuvuni.pdfIn PDF document text
    • https://bookmyexcellence.com/bookmyexcellence/js/ckfinder/userfiles/files/kevuzimipoxu.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/zeboronopowapewesusuk.pdfIn PDF document text
    • https://jurvamartin.com/userfiles/file/devavetefajutajivug.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/baguvazezawebukuxudowofos.pdfIn PDF document text
    • http://frigotechreina.com/userfiles/files/xevubuketanifiwuw.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/4pd0ut1bpofipvlk5d64thtaar/nuregewimagavamevoroti.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/65550771147.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/38316120011.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DC 11460 bytes
SHA-256: 52d699c76822f4825d0fc50447f582fac55e63ed504f822356f4d56be3fbd637
font_02_sfnt_off00011321.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11321 18096 bytes
SHA-256: 27c1b6383357b6c7505eede0758a69f5158f39ec6a63c073614b3070ab3d42ae